One glaring reality of our existence here on earth is that it has been rather short. Anatomically
modern humans have only walked the earth for about 300,000 years, and recorded history begins much
more recently. Anything that happened before the advent of writing roughly just over 5000 years ago
only survives in oral tales, often distorted by the march of time. This means that most of Earth’s
existence it has both been habitable, inhabited, but without intelligent life to record anything.
That’s literally billions of years, and earth has been broadcasting its biosignatures long enough
for anyone in the galaxy to hypothetically know about this world, and that its atmosphere is being
altered by a biosphere. Earth as a habitable planet blew its cover long before we ever
got here. So is it possible that sometime in the past, Earth was visited by an alien civilization?
The answer is yes, the universe and the laws of physics do not prohibit such a thing. Indeed,
the Fermi paradox is predicated on the notion that we really should see aliens everywhere, including
here, and for some reason we do not. This prompted Enrico Fermi to ask the question, where are they?
After all, we live in a galaxy over 13 billion years old, that’s been habitable for billions
of years before earth even formed. It’s only 100,000 light-years across, so could have been
traversed at sub light speeds by anyone many times over. You could position a von Neumann probe self
replicating and traveling at doable speeds in every star system in the Milky Way. You don’t
need an Alcubierre drive or FTL to accomplish this. All you need is time, and not that much of
it geological speaking. Only a few million years. So the question is why hasn’t anyone done this?
The answer may be simple, perhaps they have, and we just haven't been around long enough to know
about it. Unfortunately, as far as earth itself goes, we can’t ever know if anyone did. This
planet weathers evidence almost completely. We have a very incomplete fossil record as a result,
and what we do have is by sheer luck. Entire strata of rock get weathered away over time
and the action of wind and water is relentless. If an alien civilization had ever stopped by and
left any evidence of their visit, it would be unbelievably unlikely to ever find any
evidence of it. And that’s assuming they didn’t pack out their trash, leaving no traces at all.
It’s even possible that they colonized earth for a time, on some limited basis,
but the colony didn’t take and all traces of it are gone. What we do know is that they don’t
seem to have messed with the evolution and progression of life on this world,
we see no mass extinctions for example that appear to have no other possible
cause than alien over hunting. Our genome also appears unaltered, as do the genomes
of all life on earth that we’ve studied so far. Everything looks completely natural.
That’s not to say something might not be found, there have been claims within circles studying
DNA SETI that there are some odd features that might be evidence of tampering, but so far
this has not been definitive, or widely accepted within the scientific community. To quote sagan,
extraordinary claims require extraordinary evidence, and this has not been forthcoming.
But on the other hand, while earth is a bad place to look for evidence of alien life,
other areas of the solar system may be ideal. It’s even possible that some kind
of message was left just in case this planet ever produced a civilization.
One good place to look is the surface of the moon. It has been suggested that given the longevity of
objects on the moon, any equipment buried there could last for billions of years. If an alien
civilization passed through and deposited something there, say 100 million years ago,
it’s probably still there so long as it was robustly constructed. Another option,
should they not want to leave technology, would be evidence of alien biology.
This scenario is one of the more odd, but plausible ones. Fossils are rocks,
and leaving a giant prepared fossil of an animal, or the aliens themselves,
on the moon is actually doable if you want to transport it halfway across the
galaxy. Such a thing would have isotope differences far different from Earth,
and we could reasonably know we were looking at the alien equivalent of a dinosaur.
Oddly enough, there’s no reason this couldn’t happen naturally. Rock can be blasted off the
surface of the earth, including fossil bearing sedimentary rock. It’s entirely possible that
fossils from earth litter the solar system and some of the planets, such as Mars or the moon.
Conversely, fossil bearing materials could have been blasted off exoplanets to wander
the galaxy as interstellar objects, and some day, just maybe, we might confirm alien life
from an interstellar meteorite bearing fossil evidence. Entire chunks of exoplanets are
passing through our star system all the time, we need only to go study them. And while the
vast majority will not be sedimentary rock, it is in principle possible for it to be out there.
The as yet non-existent science of astropaleontology aside,
any civilization passing through might choose to leave artifacts of
technological origin. And this is where it gets spooky, as in the monolith from 2001,
or Arthur C. Clarke’s preceding short story The Sentinel. The possibilities here are endless,
you could leave some piece of technology that somehow tells the story of the alien species,
if that could be deciphered, to something a bit more scary. A warning, even an unintentional one.
This gets into the realities of recovering alien technology, so in the spirit of spooky october,
let me spin a scenario. Imagine we recovered an object of alien origin,
whether on the surface of the moon or in natural collection points where captured interstellar
objects are thought to congregate. It could be an intentional warning,
such as the deposition of materials that speak to the aliens telling us that they are highly
advanced, or be careful there’s something far worse than you realize lurking out here,
to unintentional warnings like discarded spare parts from a piece of technology.
The reason this is spooky is in how we would interpret such a finding. If we recovered a piece
of alien technology that was highly advanced, far and away more advanced than anything we’re
currently able to produce, it’s highly unlikely that we’d ever be able to determine what it is,
how it was manufactured, and what its function was. This type of back engineering will not be
easy, should it ever come to pass. If you have just a part of something, say a fragment of metal,
chances are it’s going to not be complete enough to know what it is. An example would be a car.
If you found a starter assembly of a car, but knew nothing else, you might be able to figure
out how it works to a degree, but without the rest of the car, you can’t know its function.
You just don’t have enough to reconstruct what it was, and someone just a thousand years ago
looking at a starter would not have been able to even envision what its true function was.
But it gets worse from there. A starter doesn’t tell you anything about the infrastructure needed
to operate the car. You can’t know about gasoline for example, and thusly you can’t know about gas
stations, refineries, oil wells, and so on. You are completely at a loss as to guessing
the infrastructure behind the object. This is likely with incomplete alien technology,
all we would know is that there is alien life somewhere that came here, or was sending out
materials populating the galaxy as interstellar objects, but you wouldn’t know where those aliens
are today. Might they be close by, or far away, what are the effects of finding out there is
a much, much more drastically advanced alien civilization in some kind of proximity to you?
What are their intentions, do they intend to some day seize this world? Are we being watched? If so,
why? What if the artifact is part of a weapon? What if it works on incomprehensible levels,
a technology that we can’t even envision due to an incomplete knowledge of physics. Any discovery of
an object of alien origin that we don’t know its function would automatically be spooky.
Of course there are UAP tales out there that claim this, it’s the elephant in the room and I’m just
going to outright say it, and even materials being privately held that are purportedly linked to UAP,
though isotopically most of them seem to be material originating from earth. There
are a few that are off however, intriguing, but not proof and to my knowledge none of
the described candidates appear to be complete objects, just bits and pieces. Not conclusive,
and of course there are the stories like Roswell, but those usually involve crashes
and as someone that spends their career trying to envision alien life, I can’t quite wrap my head
around a highly advanced alien civilization traveling across light years of space only
to crash into New Mexico. If true, they’re not the sharpest cookies in the drawer, and they
really need the equivalent of an FAA to ensure the safety of their vehicles. That’s assuming
however that aliens wouldn’t intentionally crash technology on a planet as a warning, they might.
But what I can say is as a kid I well remember being spooked by those stories. Anything alien
evokes the unknown, and the idea of anything alien being close is exponentially spookier. Anyone that
remembers the story of KIC 8462852, the whole reason I started this channel, will remember
a time where all we had was the Kepler data and there was a possibility that we were seeing the
activities of an alien civilization. That alone was spooky, imagine if one key thing had happened,
studies of the wavelengths of light had shown that it was solid objects blocking the light. We would
have gone deeper into megastructure construction territory, but that turned out to not be the case.
The reality is that it’s probably dust in some weird juxtaposition.
But think about it, had it been unambiguously alien, we would have been seeing a highly
advanced civilization that existed 1500 years ago constructing something
of unknown utility very distantly from Earth. People often ask me for updates on that star,
but unfortunately there’s not much to report. Observations are ongoing at several observatories,
and the question of periodicity remains. It’s unclear if the objects are in orbit of the star,
and what period they are on, or if they are something else. But what is clear overall is
that the dips are much shallower than what Kepler initially saw, suggesting a collisional model
where Kepler happened to just catch the aftermath of some colliding objects and it’s dissipated and
died down in the years since. As usual with this star though, that doesn’t explain everything,
since there is evidence in past photographic plates of dimmings previous to Kepler’s
observations. So stay tuned, the moment I hear anything more on that star, I’ll make a video.
The distance and time factor of that made that spooky. Literally looking back in time at past
aliens. But contrast that to something close. The closer the alien technology,
the spookier it is. After all, if it's in this star system, then chances are someone knows about
us. But there is one other option for evidence of a past presence of an alien civilization in
the solar system and it’s weird asteroids. So far, our asteroids look unaltered. But we’ve
only taken a close look at a very small sample compared to what’s out there in the solar system.
But an asteroid that had been mined in the past by some passing through alien civilization would
be evident in that it would basically be a bunch of tailings leftover devoid of whatever metals
they were mining. This is more benign, it would mean that some von Neumann self-replicator or
alien star ship passed through, needing to manufacture some replacement parts,
and used one of our asteroids. This does not mean they visited earth, or even cared about it,
only that they made a pit stop and then continued on their way rendezvous with
Rama style and headed off for parts unknown. And such a thing could have happened billions
of years ago for all we know, and the aliens that mined it would be long gone, or extinct.
The overarching question however is that if Earth had ever been visited in the past by aliens,
why were they here? What drew them to this place? Even if we found evidence, we may never know the
answer. But there’s one final possibility in all of this, that the technology or evidence
left behind is not defunct. But active, and merely waiting for us to discover it.
The motives, intents and capabilities of such a sleeper probe would be initially totally
unknown until it did something. It could do anything from being a benign hello machine,
to a berserker that attacks with only the slightest provocation put there by
a civilization like landmines in a warzone. What if first contact is the point that you
find that you are stuck in the middle of an enormous, slow galactic war between highly
advanced civilizations and there’s nothing you can do about it. You are only in the way.
Thanks for listening! I am futurist and science fiction author John Michael Godier currently
eyeing the dart mission dubiously. Yes, it’s great we can now move asteroids, but watching that thing
come in for the strike I was left saying to ANNA, gee I sure hope there weren’t any dinosaurs on
dimorphos. There aren’t anymore, such are the dangers of near asteroid earths with projectile
firing hominids living on them, very sordid the whole thing, and be sure to check out my books at
your favorite online book retailer and subscribe to my channels for regular, in-depth explorations
into the interesting, weird and unknown aspects of this amazing universe in which we live.